In general, engine throttle valves are assembled or manufactured to a shaft and then assembled to the air horn portion of the engine, with clearance between the two so that the valve can rotate as designed in the air horn passage to control the air flow therethrough. The assembly process, however, is often cumbersome and difficult because of the inaccessibility and/or lack of space within the air horn or throttle body to make connections for fixing the throttle shaft assembly therein. This is especially so when attempting to provide the correct clearances between the various components.
This invention relates to assembling or manufacturing a valve system in place during the composite molding of a component part, such as the air horn throttle body; with, however, the additional step of precoating the valve assembly with a meltable core material, so that after the molding process, the core material can be melted out to provide the desired clearance space between the valve system and the component part, permitting relative rotation therebetween.
Stated another way, after assembly or manufacture of the valve plates to the valve shaft, a meltable liner encompassing the latter valve system is molded around it prior to the composite molding of the part with which it cooperates.
The prior art fails to show such a method as is proposed. Those related devices that are known do provide molding in place of elastomeric type members as a part of a valve system. However, they are generally used as insulators or valve seats and are not meltable and definitely not meant to be removed, as that would destroy their function.